// by marshmellow
// takes a array of binary values, start position, length of bits per parity (includes parity bit),
-// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run)
+// Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run)
size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
{
uint32_t parityWd = 0;
}
j--; // overwrite parity with next data
// if parity fails then return 0
- if (pType == 2) { // then marker bit which should be a 1
- if (!BitStream[j]) return 0;
- } else {
- if (parityTest(parityWd, pLen, pType) == 0) return 0;
+ switch (pType) {
+ case 3: if (BitStream[j]==1) return 0; break; //should be 0 spacer bit
+ case 2: if (BitStream[j]==0) return 0; break; //should be 1 spacer bit
+ default: //test parity
+ if (parityTest(parityWd, pLen, pType) == 0) return 0; break;
}
bitCnt+=(pLen-1);
parityWd = 0;
// by marshmellow
// takes a array of binary values, length of bits per parity (includes parity bit),
-// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run)
+// Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
+// Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType)
{
uint32_t parityWd = 0;
dest[j++] = (BitSource[word+bit]);
}
// if parity fails then return 0
- if (pType == 2) { // then marker bit which should be a 1
- dest[j++]=1;
- } else {
- dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
+ switch (pType) {
+ case 3: dest[j++]=0; break; // marker bit which should be a 0
+ case 2: dest[j++]=1; break; // marker bit which should be a 1
+ default:
+ dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
+ break;
}
bitCnt += pLen;
parityWd = 0;
size_t numBits = 0;
// count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
- // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
+ // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
// between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
for(idx = 161; idx < size-20; idx++) {
// threshold current value
return (int) startIdx;
}
+// find presco preamble 0x10D in already demoded data
+int PrescoDemod(uint8_t *dest, size_t *size) {
+ //make sure buffer has data
+ if (*size < 64*2) return -2;
+
+ size_t startIdx = 0;
+ uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -4; //preamble not found
+ //return start position
+ return (int) startIdx;
+}
+
// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
// BitStream must contain previously askrawdemod and biphasedemoded data
int FDXBdemodBI(uint8_t *dest, size_t *size)
uint8_t fndClk[] = {8,16,32,40,50,64,128};
int clk = 0;
int tol = 0;
- int i, j, skip, start, end, low, high, minClk;
+ int i, j, skip, start, end, low, high, minClk, waveStart;
bool complete = false;
int tmpbuff[bufsize / 64];
+ int waveLen[bufsize / 64];
size_t testsize = (bufsize < 512) ? bufsize : 512;
- //int phaseoff = 0;
+ int phaseoff = 0;
high = low = 128;
memset(tmpbuff, 0, sizeof(tmpbuff));
if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
return false; //just noise
}
-
i = 0;
j = 0;
minClk = 255;
start= i;
while ((buffer[i] < high) && (i < bufsize))
++i;
+ //first high point for this wave
+ waveStart = i;
while ((buffer[i] > low) && (i < bufsize))
++i;
if (j >= (bufsize/64)) {
break;
}
+ waveLen[j] = i - waveStart; //first high to first low
tmpbuff[j++] = i - start;
if (i-start < minClk && i < bufsize) {
minClk = i - start;
start = -1;
for (i = 0; i < j - 4; ++i) {
skip += tmpbuff[i];
- if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior
- if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol) { //2 clocks
- if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol) { //1 1/2 to 2 clocks
- if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= (clk*3)/2+tol) { //1 to 1 1/2 clocks for end of ST + first bit
+ if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior
+ if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2
+ if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
+ if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
start = i + 3;
break;
}
if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
return false;
}
-
+ if (waveLen[i+2] > clk*1+tol)
+ phaseoff = 0;
+ else
+ phaseoff = clk/2;
+
// skip over the remainder of ST
skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
for (i += 3; i < j - 4; ++i) {
end += tmpbuff[i];
if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior
- if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol) { //2 clocks
- if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol) { //1 1/2 to 2 clocks
- if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= (clk*3)/2+tol) { //1 to 1 1/2 clocks for end of ST + first bit
+ if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2
+ if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
+ if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
complete = true;
break;
}
}
}
}
+ end -= phaseoff;
//didn't find second ST - ERROR
if (!complete) {
if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
return false;
}
- if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d", skip, end, end-skip, clk, (end-skip)/clk);
+ if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff);
//now begin to trim out ST so we can use normal demod cmds
start = skip;
size_t datalen = end - start;
projects / proxmark3-svn / blobdiff